Chromosome 12, trisomy 12q, also known as duplication 12q, is a rare genetic condition. This condition results from a mutation or error in a person’s DNA or genes. This can cause birth defects such as low muscle tone and severe developmental delays, as well as feeding problems at birth, very severe reflux (spitting up), and stomach and digestive problems. Although there is currently no cure for chromosome 12, trisomy 12q, there are various resources to help manage the condition and treat birth defects. Speech therapists are sometimes able to help children with feeding difficulties. Doctors seek help from various therapists and community services to provide support and care for families affected by chromosome 12, trisomy 12q.